Functionalized bile acids for therapeutic and material applications

ABSTRACT

The subject disclosure is directed to functionalized bile acids, preparation thereof, and usage thereof for therapeutic and material applications. In one embodiment, a method of generating functionalized bile acid materials can comprise directly activating a carboxylic acid of a bile acid compound using a coupling agent comprising an amide or ester compound, thereby generating an intermediate bile acid derivative material. The method can further comprise attaching a functional group material to the intermediate bile acid derivative material by reacting the functional group material and the intermediate bile acid derivative material, thereby generating a functionalized bile acid material.

TECHNICAL FIELD

This application generally relates to functionalized bile acids,preparation thereof, and usage thereof for therapeutic and materialapplications.

SUMMARY

The following presents a summary to provide a basic understanding of oneor more embodiments of the invention. This summary is not intended toidentify key or critical elements, or delineate any scope of thedifferent embodiments or any scope of the claims. Its sole purpose is topresent concepts in a simplified form as a prelude to the more detaileddescription that is presented later. The subject disclosure relates tofunctionalized bile acids, preparation thereof, and usage thereof fortherapeutic and material application.

According to an embodiment, a method is provided for attachingfunctional groups to bile acids that comprises directly activating acarboxylic acid of a bile acid compound using a coupling agentcomprising an amide or ester compound, thereby generating anintermediate bile acid derivative material. The method further comprisesattaching a functional group material to the intermediate bile acidderivative material by reacting the functional group material and theintermediate bile acid derivative material, thereby generating afunctionalized bile acid material. In various embodiments, the couplingagent comprises pentafluorophenyl carbonate.

In some implementations, the functional group material comprises a smallmolecule, particularly a small molecule amine. With theseimplementations, the functionalized bile acid material generated basedon reaction of the small molecule amine and the intermediate bile acidmaterial comprises a bile acid amide. In one embodiment, the method canfurther comprise attaching a polymer to a functional group of the bileacid amide, thereby generating a functionalized bile acid polymer. Inother implementations, the functional group material can comprise amacromolecular amine, thus making the resulting functionalized bile acidmaterial a bile acid macromolecule amide.

In various embodiments, the functional group material can comprise apolymer that provides therapeutic properties. With these embodiments,the functionalized bile acid material can be therapeutic material itselfor serve as a therapeutic material carrier. In another implementation,the functional group material can comprise a polymer that hasdisinfectant properties, thereby making the functional bile acidmaterial a disinfectant. Further, in some implementations in which thefunctional group material comprises a polymer that makes thefunctionalized bile acid material therapeutic material or a therapeuticmaterial carrier, the functionalized bile acid material can cross ablood brain barrier in association with providing therapeuticfunctionality.

In another embodiment, a functionalized bile acid material is providedthat comprises a chemical structure of Structure I:

wherein R comprises a bile acid steroid backbone, and

wherein X comprises a polymer.

In some implementations, the polymer X comprises an amine terminatedpolymer. In another implementation, the polymer X comprises a materialselected from the group comprising polyethylene glycol and polyethyleneamine. In another implementation, the polymer can comprise a diblockpolycarbonate copolymer. For example, in accordance with thisimplementation, the functionalized bile acid material can comprise thechemical structure II:

In another embodiment, a method is provided that comprises generating anintermediate bile acid derivative material by directly activating acarboxylic acid of a bile acid compound using a coupling agentcomprising an amide or ester compound. The method further comprisesgenerating a functionalized bile acid material using the intermediatebile acid derivative material, wherein the functionalized bile acidmaterial comprises a chemical structure of structure I:

wherein R comprises a bile acid steroid backbone, and

wherein X comprises a nucleophile selected from a group consisting ofsmall molecule amines and macromolecular amines.

In various implementations, the coupling agent comprisespentafluorophenyl carbonate. In some implementations, the process ofgenerating the functionalized bile acid material comprises attaching theamine nucleophile X to the intermediate bile acid derivative material bydirectly reacting the nucleophile with the intermediate bile acidderivative material. Reaction of the intermediate bile acid derivativematerial with the amine nucleophile X renders the resultingfunctionalized bile acid material having Structure I a bile acid amide.

In another implementation, the method further comprising, generating afunctionalized bile acid polymer using the functionalized bile acidmaterial having structure I. With this implementation, the method canfurther comprise attaching the functionalized bile acid material havingStructure I to a polymer via a functional group of the nucleophile X,thereby generating the corresponding functionalized bile acid polymer.For example, in accordance with one implementation in which thenucleophile X comprises an amide functional group, a diblockpolycarbonate copolymer can be attached to the functionalized bile acidmaterial (or vice versa) via the amide functional group, resulting in afunctionalized bile acid polymer comprising chemical Structure II:

BRIEF DESCRIPTION OF THE DRAWINGS

Numerous aspects, embodiments, objects and advantages of the presentinvention will be apparent upon consideration of the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like reference characters refer to like parts throughout, and inwhich:

FIG. 1 presents example, non-limiting structures of different bile acidsin accordance with various aspects and embodiments described herein.

FIG. 2 presents an example, non-limiting synthesis route for generatingfunctionalized bile acid materials in accordance with various aspectsand embodiments described herein.

FIG. 3 presents some example, non-limiting bile acid amides generatedbased on functionalization of a bile acid with different small moleculeamines in accordance with various aspects and embodiments of the subjectdisclosure.

FIG. 4 presents some example, non-limiting macromolecular bile acidamides generated based on functionalization of a bile acid withdifferent macromolecular amines in accordance with various aspects andembodiments of the subject disclosure.

FIG. 5 presents an example, non-limiting synthesis route for generatingfunctionalized bile acid polymers in accordance with various aspects andembodiments described herein.

FIG. 6 presents an example, non-limiting synthesis route for generatinga cationic, bile acid functionalized polycarbonate compound inaccordance with various aspects and embodiments described herein.

FIG. 7 provides an example, non-limiting method of generatingfunctionalized bile acid materials in accordance with various aspectsand embodiments described herein.

FIG. 8 provides an example, non-limiting method of generatingfunctionalized bile acid materials in accordance with various aspectsand embodiments described herein.

FIG. 9 provides an example, non-limiting method of generatingfunctionalized bile acid materials in accordance with various aspectsand embodiments described herein.

FIG. 10 provides an example, non-limiting method of treating a subjecthaving cancer in accordance with various aspects and embodimentsdescribed herein.

DETAILED DESCRIPTION

The following detailed description is merely illustrative and is notintended to limit embodiments and/or application or uses of embodiments.Furthermore, there is no intention to be bound by any expressed orimplied information presented in the preceding Summary section or in theDetailed Description section.

The subject disclosure relates to functionalized bile acids, preparationthereof, and usage thereof for therapeutic and material applications.Bile acids are naturally occurring steroidal compounds that aid in thesolubilizing and transport of dietary fats. Their function asemulsifiers stems from the presence of polar functional groups such ascarboxylic acids and hydroxyl groups on the otherwise non-polar steroidbackbone, affording amphiphilic properties to bile acids. The subjectdisclosure provides effective strategies for the preparation offunctionalized bile acid materials that exploit the amphiphilic natureof bile acids. In this regard, the subject disclosure provides a robustsynthetic protocol for the preparation of a wide array of bile acidfunctionalized materials and macromolecules using a simple amidecoupling procedure based on the use of the commercially availablepentafluorophenyl carbonate. In particular, the pentafluorophenylcarbonate can be used as an amide and ester coupling agent for thedirect synthesis of bile acid functionalized materials and conjugates ofbile acids with small molecule amines. This coupling reaction iscompatible with a large variety of macromolecular and small moleculeamines as well as both primary or secondary amines.

In one or more embodiments, the carboxylic acid of a bile acid can bedirectly activated by treatment with the pentafluorophenyl carbonate inthe presence of base to generate the corresponding pentafluorophenylester. The in situ generated pentafluorophenyl ester can then bedirectly reacted with a variety of primary and secondary amines toproduce the corresponding bile acid amides. Using this approach, avariety of small molecule amines can be used to generate thecorresponding bile acid amides. Macromolecular amines can also beutilized to produce the corresponding bile acid functionalizedmacromolecules. Finally, the prepared bile acid amides can be used forthe post-synthesis functionalization of polymers.

The use of pentafluorophenyl carbonate is highly advantageous due to itsease of handling and low toxicity compared to standard amide basedcoupling reagents typically used in the preparation of bile acidmaterials. In addition, by using pentafluorophenyl carbonate as acoupling agent, the disclosed techniques for preparing bile acidmaterials do not result in undesirable byproducts, such as urea, thatare difficult to remove and typically generated in traditional amidecoupling reactions. Further, by using pentafluorophenyl carbonate as thecoupling agent, no additional activating agent such as1-hydroxybenzotriazole or N-hydroxysuccinimide are required, reducingthe number of impurities and byproducts that must be removed during thework-up and purification. Finally, the short reaction times andstraightforward reaction setup make this approach a highly desirablealternative to preparing both bile acid small molecule conjugates andbile acid functionalized materials.

The resulting functionalized bile acid materials can provide variousmaterial applications. For example, in some embodiments, the bile acidmaterials can provide biomedical applications, including application astherapeutic carriers and therapeutics themselves. For example, one ormore bile acid materials generated using the disclosed techniques can beused as vehicles for medication delivery, ribonucleic acid (RNA)delivery, and the formation of polymer-virus complexes for cancertherapy. In some embodiments, by exploiting the ability for bile acidsto pass through epithelial layers in association with transportingnutrients and vitamins into the blood stream, one or more of thedisclosed bile acid derivative materials can provide biomedicalapplications that involve providing therapeutics that can cross theblood brain barrier. Further, small molecule bile acid derivatives thatcan be synthesized using the disclosed techniques can provideself-assembly properties or be utilized as antimicrobial agents.

Various embodiments of the subject disclosure describe techniques forsynthesizing bile acid derivative materials. The subject disclosureprovides some example laboratory processes that were used to synthesizesome of the subject bile acid derivatives. These example laboratoryprocedures are respectively identified as Synthesis Example 1, SynthesisExample 2, Synthesis Example 3, Synthesis Example 4, Synthesis Example 5and Synthesis Example 6. These example laboratory synthetizationprocedures were respectively carried out on the benchtop using benchtopsolvents unless otherwise noted. All commercially available reagents andsolvents were used as received. The ¹H- and ¹³C-NMR spectra of monomersand polymers were recorded using a Bruker Avance 400 spectrometer,operated at 400 and 100 MHz respectively, with the solvent proton signalas the internal reference standard.

It should be appreciated however that the example laboratory processdescribed with respect to Synthesis Example 1, Synthesis Example 2,Synthesis Example 3, Synthesis Example 4, Synthesis Example 5 andSynthesis Example 6 are intended merely to demonstrate one examplesynthetization procedure that can be employed to generate correspondingbile acid derivative materials. In this regard, at least some of thereagents, solvents, material concentrations, temperatures, durations,and procedural conditions described with respect to the examplelaboratory procedures employed can vary.

One or more embodiments are now described with reference to thedrawings, wherein like referenced numerals are used to refer to likeelements throughout. In the following description, for purposes ofexplanation, numerous specific details are set forth in order to providea more thorough understanding of the one or more embodiments. It isevident, however, in various cases, that the one or more embodiments canbe practiced without these specific details.

Turning now to the drawings, FIG. 1 presents some example chemicalstructures 1A, 1B, 1C, 1D and 1E of different bile acids accordance withvarious aspects and embodiments described herein. As shown in FIG. 1,the bile acids respectively include one or more polar functional groupssuch as carboxylic acids and hydroxyl groups on an otherwise non-polarsteroid backbone, affording them amphiphilic properties.

FIG. 2 presents an example synthesis route 200 for generatingfunctionalized bile acid materials in accordance with various aspectsand embodiments described herein. In the embodiment shown, thecarboxylic acid group of a bile acid 2A can be directly activated bytreatment with the pentafluorophenyl carbonate 2B in the presence of abase to generate an intermediate bile acid derivative material; thecorresponding pentafluorophenyl ester 2C. Some suitable base materialsthat can be employed include but are not limited to: triethylamine,diisopropylethylamine, 1,8-Diazabicyclo[5.4.0]undec-7-ene, or potassiumcarbonate. In one or more embodiments, the pentafluorophenyl ester 2Ccan be generated in situ. The bile acid 2A can vary. For example, thebile acid 2A can include any of the bile acids shown in FIG. 1 as wellas other existing bile acids. The portion of the bile acid 2Arepresented by the variable R corresponds to the steroid backbone of thebile acid.

The pentafluorophenyl ester 2C can then be directly reacted with avariety of nucleophiles X to generate the resulting functionalized bileacid material 2D having the following chemical structure I:

wherein R comprises a bile acid steroid backbone, and

wherein X comprises a nucleophile.

In one or more embodiments, the nucleophile X can include variousprimary and secondary amines, thereby making the resultingfunctionalized bile acid material 2D a bile acid amide. In this regard,the small molecule amine can be attached to the pentafluorophenyl estervia an amide bond (or an amide bond forming reaction). Using thisapproach, a variety of small molecule amines can be used as thenucleophile X to generate the corresponding bile acid amides. Forexample, some example suitable primary amines that can be employed asthe nucleophile X can include but are not limited to: ethanolamine,N,N-dimethylethylenediamine, 1-(3-aminopropyl)imidazole, benzylamine, or2-Amino-2-methylpropane-1,3-diol. Some example suitable secondary aminesthat can be employed as the nucleophile X can include but are notlimited to: diethanolamine, N,N,N′-trimethylethylenediamine, morpholine,1-methylpiperazine, or 3,3′-iminobis(N,N-dimethylpropyl amine).

FIG. 3 presents some example bile acid amides 3A, 3B, 3C and 3D that canbe generated based on functionalization of a bile acid (e.g., bile acid2A) with different small molecule amines in accordance with variousaspects and embodiments of the subject disclosure. In the embodimentshown, the bile acid amides 3A, 3B, 3C and 3D respectively comprisedifferent small molecule amines attached to the carboxylic acid portionof a bile acid. In this regard, the nucleophile X can comprise a smallmolecule amine.

With reference again to FIG. 2, one example implementation of synthesisroute 200 was carried out to generate a functionalized bile acidmaterial having structure I as follows:

-   -   A vial equipped with a magnetic stir bar was charged with bile        acid (1.0 equivalent), pentafluorophenyl carbonate (1.0        equivalent), and CH₂Cl₂ (1.0 M). The reaction mixture was        stirred at room temperature and Et₃N (1.2 equivalent) was added.        The reaction mixture became homogenous and carbon dioxide was        liberated. The reaction mixture was stirred at room temperature        for an additional 1 hour and the amine (1.2 equivalent) was        added. The reaction was stirred for an additional 3-18 hours        before being subjected to workup and purification.

Synthesis Example 1

Synthesis Example 1 describe one example general procedure for thefunctionalization of bile acids in accordance with synthesis route 200.It should be appreciated however that Synthesis Example 1 is merelyintended to demonstrate one example synthetization procedure that can beemployed to generate the corresponding bile acid derivative materialhaving Structure I. In this regard, at least some of the reagents,solvents, material concentrations, temperatures, durations, andprocedural conditions described can vary. Further, Synthesis Example 1is not intended to limit the scope of synthesis route 200.

In one or more additional embodiments, the nucleophile X of structure Ican comprise a macromolecular amine. In this regard, the macromolecularamine can be attached to the pentafluorophenyl ester via an amide bond(or an amide bond forming reaction). With these embodiments, synthesisroute 200 can also be utilized to produce functionalized bile acidmacromolecule amides. Some suitable macromolecular amines that can beemployed as the nucleophile X of Structure I can include but are notlimited to: α,ω-PEG diamine, polyethyleneimine, or jeffamines.

For example, FIG. 4 presents some example macromolecular bile acidamides 4A and 4B that can be generated based on functionalization of abile acid with different macromolecular amines in accordance withvarious aspects and embodiments of the subject disclosure. In theembodiment shown, the macromolecular amine used to generate thecorresponding macromolecule bile acid amide 4A using synthesis route 200comprises polyethylene glycol (PEG), an amine terminated polymer. Thenumber average molecular weight (M_(n)) of the PEG chain can vary. Forexample, in one implementation, the PEG chain can be about 4600 M_(n).In another implementation, the PEG can be 8000 M_(n). The macromolecularamine used to generate the corresponding macromolecular bile acid amide4B using synthesis route 200 comprises branched polyethylenimine (PEI),another amine terminated polymer. The size of the PEI used can alsovary. For example, in one implementation, the PEI can have an M_(n) ofabout 10,000. The bile acids used to generate the macromolecular bileacid amides 4A and 4B can also vary. For example, in one implementation,the molecule represented by the variable R in the macromolecular bileacid amides 4B can hydrogen. In another implementation, the R canrepresent a hydroxyl group. In one or more embodiments, themacromolecular bile acid amides 4A and 4B can be used as therapeuticcarriers.

One example implementation of synthesis route 200 was carried out togenerate the macromolecular bile acid amide 4A with an M_(n) of 4600 asfollows:

-   -   Following the above described Synthesis Example 1 for generating        the functionalized bile acid material 2D in accordance with        synthesis route 200, a vial was charged with lithocholic acid        (103 mg, 0.27 mmol), pentafluorophenyl carbonate (107 mg, 0.27        mmol), and CH₂Cl₂ (1 mL). Et₃N (42 μL, 0.30 mmol) was added and        the reaction mixture became homogenous. After stirring at room        temperature for 2 h, amine-terminated PEG (M_(n)=4600, 500 mg,        0.11 mmol) was added and the reaction mixture was stirred at        room temperature for 24 hours. The reaction mixture was then        transferred to a dialysis bag (1000 MWCO) and dialyzed against        CH₂Cl₂:MeOH (1:1) for 24 hours, changing the solvent three        times. After dialysis, the polymer was precipitated twice from        Et₂O to isolate the desired lithocholic acid functionalized PEG        (95% functionalization). ¹H NMR (CDCl₃) δ 6.05 (m, 1H), 3.64 (m,        410H), 3.45 (m, 7H), 2.24 (m, 2H), 2.07 (m, 2H), 1.80-1.52 (m,        24H), 1.40-1.05 (m, 34H), 0.91 (m, 12H), 0.63 (m, 6H).

Synthesis Example 2

One example implementation of synthesis route 200 was carried out togenerate the macromolecular bile acid amide 4A with an M_(n) of 8000 asfollows:

-   -   Following the above described Synthesis Example 1 for generating        the functionalized bile acid material 2D in accordance with        synthesis route 200, a vial was charged with lithocholic acid        (103 mg, 0.27 mmol), pentafluorophenyl carbonate (107 mg, 0.27        mmol), and CH₂Cl₂ (1 mL). Et₃N (42 μL, 0.30 mmol) was added and        the reaction mixture became homogenous. After stirring at room        temperature for 2 h, amine-terminated PEG (M_(n)=8000, 500 mg,        0.11 mmol) was added and the reaction mixture was stirred at        room temperature for 24 hours. The reaction mixture was then        transferred to a dialysis bag (1000 MWCO) and dialyzed against        CH₂Cl₂:MeOH (1:1) for 24 hours, changing the solvent three        times. After dialysis, the polymer was precipitated twice from        Et₂O to isolate the desired lithocholic acid functionalized PEG        (80% functionalization). ¹H NMR (CDCl₃) δ 6.05 (m, 1H), 3.64 (m,        719H), 3.45 (m, 10H), 2.24 (m, 2H), 2.07 (m, 2H), 1.80-1.52 (m,        24H), 1.40-1.05 (m, 28H), 0.91 (m, 10H), 0.63 (m, 5H).

Synthesis Example 3

One example implementation of synthesis route 200 was carried out togenerate the macromolecular bile acid amide 4B wherein the variable Rcomprises hydrogen was carried out as follows:

-   -   Following the above described Synthesis Example 1 for generating        the functionalized bile acid material 2D in accordance with        synthesis route 200, a vial was charged with lithocholic acid        (147 mg, 0.36 mmol), pentafluorophenyl carbonate (142 mg, 0.36        mmol), and DMF (3 mL). Et₃N (60 μL, 0.43 mmol) was added and the        reaction mixture was stirred for 2 hours at room temperature.        After 2 hours, the reaction mixture was added via syringe to a        stirred solution of branched PEI (M_(n)=10000, 400 mg, 0.04        mmol) in DMF (3 mL) and stirred at room temperature for 24        hours. The reaction mixture was then transferred to a dialysis        bag (1000 MWCO) and dialyzed against CH₂Cl₂:MeOH (1:1) for 24        hours, changing the solvent three times. Following dialysis, the        solvent was removed to afford the lithocholic acid        functionalized branched PEI. ¹H NMR (MeOD) δ 3.51 (m, 2H), 3.41        (m, 2H), 2.86-2.63 (m, 91H), 2.22 (m, 2H), 2.06 (m, 2H), 1.96        (m, 1H), 1.85 (m, 1H), 1.70 (m, 3H), 1.57 (m, 2H), 1.38 (m, 8H),        1.28-0.98 (m, 15H), 0.91 (m, 6H), 0.65 (m, 3H).

Synthesis Example 4

One example implementation of synthesis route 200 was carried out togenerate the macromolecular bile acid amide 4B wherein the variable Rcomprises a hydroxyl was carried out as follows:

-   -   Following the above described Synthesis Example 1 for generating        the functionalized bile acid material 2D in accordance with        synthesis route 200, a vial was charged with cholic acid (147        mg, 0.36 mmol), pentafluorophenyl carbonate (142 mg, 0.36 mmol),        and DMF (3 mL). Et₃N (60 μL, 0.43 mmol) was added and the        reaction mixture was stirred for 2 hours at room temperature.        After 2 hours, the reaction mixture was added via syringe to a        stirred solution of branched PEI (M_(n)=10000, 400 mg, 0.04        mmol) in DMF (3 mL) and stirred at room temperature for 24        hours. The reaction mixture was then transferred to a dialysis        bag (1000 MWCO) and dialyzed against CH₂Cl₂:MeOH (1:1) for 24        hours, changing the solvent three times. Following dialysis, the        solvent was removed to afford the cholic acid functionalized        branched PEI. ¹H NMR (MeOD) δ 3.95 (m, 1H), 3.79 (m, 1H),        3.48-3.13 (m, 10H), 2.83-2.64 (m, 118H), 2.27 (m, 4H), 1.90-1.79        (m, 10H), 1.58-1.29 (m, 14H), 1.13-0.95 (m, 6H), 0.92 (m, 3H),        0.71 (m, 3H).

Synthesis Example 5

Synthesis Examples 2-5 describe respectively describe example proceduresfor generation of macromolecular bile acid amides in accordance withsynthesis route 200. It should be appreciated however that SynthesisExamples 2-5 are merely exemplary and at least some of the reagents,solvents, material concentrations, temperatures, durations, andprocedural conditions described can vary. Further, Synthesis Examples2-5 are not intended to limit the scope of synthesis route 200.

With reference again to FIGS. 1 and 3, in some implementations, the bileacid amides having chemical structure I above, wherein X comprises asmall molecule amine (e.g., bile acid amides 3A, 3B, 3C, and 3D), can beused as disinfectants. In other implementations, the prepared bile acidamides can be used for the post-synthesis functionalization of polymers.With these implementations, a bile acid amide (e.g., bile acid amides3A, 3B, 3C, 3D and the like), can be attached to the polymer backbonevia a functional group of the small molecule amine. In this regard, theamide bond forming reaction between the small molecule amine and thepentafluorophenyl ester 2C can be used to combine the bile acid 2A withan amine having one or more specific functional groups which can then beattached to different polymer backbones.

For example, FIG. 5 presents an example synthesis route for 500generating functionalized bile acid polymers in accordance with variousaspects and embodiments described herein. In the embodiment shown, thefunctionalized bile acid material 2D having structure I above, (whereinX comprises a small molecule amine), can be directly reacted with apolymer Y to generate the corresponding functionalized bile acid polymer5A having the following chemical structure III:

wherein R comprises a bile acid steroid backbone,

wherein X′ comprises a reacted nucleophile, and

wherein Y comprises a polymer.

The polymer Y can vary. For example, in one or more embodiments, thepolymer Y can include any suitable polymer having the followingproperties that include having a requisite functional group handle toenable incorporation of a functionalized bile acid. These groups mayinclude, but not limited to: azides, alkynes, alkyl halides, benzylhalides, thioethers, disulfides, epoxides, thiols, alcohols, diols,esters, or boronic acids. For example, the polymer Y can include but isnot limited to: polycarbonates, polyurethanes, polylysines,polyethyleneimines, polyionenes, polyacrylates, or other appropriatelyfunctionalized polymer. The reacted nucleophile X′ corresponds to anucleophile having a functional group that been attached to the polymerbackbone via reaction of the functionalized bile acid material 2D withthe polymer Y. In one embodiment, a new bile acid functionalized polymerthat provides anti-cancer therapeutic functionality can be generatedusing synthesis routes 200 and 500. This new bile acid functionalizedpolymer comprises a cationic, bile acid functionalized polycarbonatecompound and is referred to herein as lithocholic acid functionalizedpolycarbonate.

FIG. 6 presents an example synthesis route 600 for generating alithocholic acid functionalized polycarbonate in accordance with variousaspects and embodiments described herein. In the embodiment shown, thebile acid amide 3C can be directly reacted with AB diblock polycarbonatecopolymer 6A (e.g., a copolymer comprising PEG and polycarbonate) togenerated the resulting lithocholic acid functionalized polycarbonate6B, a cationic, bile acid functionalized polycarbonate compound. In thissynthesis route 600, the nitrogen dimethyl or dimethylamine (NMe₂)functional group of the bile acid amide 3C can be quaternized to attachit to the dependent chlorobenzene of the copolymer 6A, thereby resultingin the lithocholic acid functionalized polycarbonate 6B.

One example implementation of synthesis route 500 was carried out togenerate the lithocholic acid functionalized polycarbonate 6B, wascarried out as follows:

-   -   A vial equipped with a magnetic stir-bar was charged with the        bile acid amide 3C (100 mg) and the copolymer 6A (112 mg, 0.25        mmol). MeCN (2 mL) and CH₂Cl₂ (1 mL) were added and the reaction        mixture was heated to 50° C. in a sand bath for 18 hours. After        cooling to room temperature, the reaction mixture was then        transferred to a dialysis bag (1000 MWCO) and dialyzed against        CH₂Cl₂:MeOH (1:1) for 24 hours, changing the solvent three        times. Following dialysis, the solvent was removed to afford the        lithocholic acid functionalized polycarbonate 6B (>95%        functionalization). ¹H NMR (DMSO) δ 7.58 (m, 20H), 7.46 (m,        20H), 5.18 (m, 26H), 4.60-4.50 (m, 30H), 4.23-4.11 (m, 40H),        3.51 (m, 452H), 3.24 (m, 3H), 3.00 (m, 48H), 2.12 (m, 10H), 2.03        (m, 10H), 1.91 (m, 10H), 1.77-1.51 (m, 65H), 1.33-1.01 (m,        169H), 0.86 (m, 58H), 0.59 (m, 26H).

Synthesis Example 6

Synthesis Example 6 describes one example procedures for the generationof the lithocholic acid functionalized polycarbonate 6B in accordancewith synthesis route 500. It should be appreciated however thatSynthesis Example 6 is merely exemplary and at least some of thereagents, solvents, material concentrations, temperatures, durations,and procedural conditions described can vary. Further, SynthesisExamples 6 is not intended to limit the scope of synthesis route 500.

FIGS. 7-10 illustrate various methodologies in accordance with thedisclosed subject matter. While, for purposes of simplicity ofexplanation, the methodologies are shown and described as a series ofacts, it is to be understood and appreciated that the disclosed subjectmatter is not limited by the order of acts, as some acts can occur indifferent orders and/or concurrently with other acts from that shown anddescribed herein. For example, those skilled in the art will understandand appreciate that a methodology could alternatively be represented asa series of interrelated states or events, such as in a state diagram.Moreover, not all illustrated acts can be required to implement amethodology in accordance with the disclosed subject matter. Repetitivedescription of like elements employed in respective embodiments isomitted for sake of brevity.

FIG. 7 provides an example method 700 for generating functionalized bileacid materials in accordance with various aspects and embodimentsdescribed herein. At 702, a carboxylic acid of a bile acid compound canbe directly activated using pentafluorophenyl carbonate as a couplingagent, thereby generating an intermediate bile acid derivative material(e.g., pentafluorophenyl ester 2C). At 704, the intermediate bile acidderivative material can be employed to generate a functionalized bileacid material (e.g., a functionalized bile acid materials havingStructure I, Structure II, or Structure III, described herein).

FIG. 8 provides an example method 800 for generating functionalized bileacid materials in accordance with various aspects and embodimentsdescribed herein. At 802, a carboxylic acid of a bile acid compound canbe directly activated using a coupling agent comprising an amide orester compound, thereby generating an intermediate bile acid derivativematerial (e.g., pentafluorophenyl ester 2C). At 804, a functional groupmaterial (e.g., a small molecule amine, a macromolecular amine, and thelike) can be attached to the intermediate bile acid derivative materialby reacting the functional group material and the intermediate bile acidderivative material, thereby generating a functionalized bile acidmaterial (e.g., a functionalized bile acid material comprising StructureI).

FIG. 9 provides an example method 900 for generating functionalized bileacid materials in accordance with various aspects and embodimentsdescribed herein. At 902, a carboxylic acid of a bile acid compound canbe directly activated using a coupling agent comprising an amide orester compound, thereby generating an intermediate bile acid derivativematerial (e.g., pentafluorophenyl ester 2C). At 904, a small moleculeamine can be reacted with the intermediate bile acid derivativematerial, thereby generating a functionalized bile acid amide (e.g., abile acid amide 3C). At 906, the functionalized bile acid amide can bereacted with a polymer comprising a first functional group configured toreact with a second functional group of the bile acid amide, therebygenerating a functionalized bile acid polymer (e.g., functionalized bileacid polymer comprising Structures II and/or III).

FIG. 10 provides an example method 1000 for treating a subject havingcancer in accordance with various aspects and embodiments describedherein. At 1002, a therapeutic compound can be generated that comprisesa functionalized bile acid polymer comprising a chemical structure ofStructure II as defined herein. At 1004, the therapeutic compound can beadministered to a subject having cancer or tumor cells, thereby reducingor preventing growth of the cancer or tumor cells as a result of theadministering.

What has been described above includes examples of the embodiments ofthe present invention. It is, of course, not possible to describe everyconceivable combination of components or methodologies for purposes ofdescribing the claimed subject matter, but it is to be appreciated thatmany further combinations and permutations of the subject innovation arepossible. Accordingly, the claimed subject matter is intended to embraceall such alterations, modifications, and variations that fall within thespirit and scope of the appended claims. Moreover, the above descriptionof illustrated embodiments of the subject disclosure, including what isdescribed in the Abstract, is not intended to be exhaustive or to limitthe disclosed embodiments to the precise forms disclosed. While specificembodiments and examples are described in this disclosure forillustrative purposes, various modifications are possible that areconsidered within the scope of such embodiments and examples, as thoseskilled in the relevant art can recognize.

In this regard, with respect to any figure or numerical range for agiven characteristic, a figure or a parameter from one range may becombined with another figure or a parameter from a different range forthe same characteristic to generate a numerical range. Other than in theoperating examples, or where otherwise indicated, all numbers, valuesand/or expressions referring to quantities of ingredients, reactionconditions, etc., used in the specification and claims are to beunderstood as modified in all instances by the term “about.”

While there has been illustrated and described what are presentlyconsidered to be example features, it will be understood by thoseskilled in the art that various other modifications may be made, andequivalents may be substituted, without departing from claimed subjectmatter. Additionally, many modifications may be made to adapt aparticular situation to the teachings of claimed subject matter withoutdeparting from the central concept described herein. Therefore, it isintended that claimed subject matter not be limited to the particularexamples disclosed, but that such claimed subject matter may alsoinclude all aspects falling within the scope of appended claims, andequivalents thereof.

In addition, while a particular feature of the subject innovation mayhave been disclosed with respect to only one of several implementations,such feature may be combined with one or more other features of theother implementations as may be desired and advantageous for any givenor particular application. Furthermore, to the extent that the terms“includes,” “including,” “has,” “contains,” variants thereof, and othersimilar words are used in either the detailed description or the claims,these terms are intended to be inclusive in a manner similar to the term“comprising” as an open transition word without precluding anyadditional or other elements.

Moreover, the words “example” or “exemplary” are used in this disclosureto mean serving as an example, instance, or illustration. Any aspect ordesign described in this disclosure as “exemplary” is not necessarily tobe construed as preferred or advantageous over other aspects or designs.Rather, use of the words “example” or “exemplary” is intended to presentconcepts in a concrete fashion. As used in this application, the term“or” is intended to mean an inclusive “or” rather than an exclusive“or”. That is, unless specified otherwise, or clear from context, “Xemploys A or B” is intended to mean any of the natural inclusivepermutations. That is, if X employs A; X employs B; or X employs both Aand B, then “X employs A or B” is satisfied under any of the foregoinginstances. In addition, the articles “a” and “an” as used in thisapplication and the appended claims should generally be construed tomean “one or more” unless specified otherwise or clear from context tobe directed to a singular form.

What is claimed is:
 1. A functionalized bile acid polymer having achemical structure of Structure I:

wherein R corresponds to a steroid backbone of a bile acid selected fromthe group consisting of cholic acid, chenodeoxycholic acid, lithocholicacid, deoxycholic acid, and glycocholic acid; wherein X′ corresponds toan amine nucleophilic compound selected from the group consisting of:diethanolamine, N,N,N′-trimethylethylenediamine, 1-methylpiperazine,3,3′-iminobis(N,N-dimethylpropyl amine),2-amino-2-methyl-1,3-propanediol, (4-(aminomethyl)phenyl)boronic acid,1-(3-aminopropyl)imidazole, and benzylamine; and wherein Y correspondsto a polymer selected from the group consisting of a polycarbonate,polylysine, polyethyleneimine, polyionene, and polyacrylate.
 2. Thefunctionalized bile acid polymer of claim 1, wherein the polymercomprises a functional group handle covalently bonded to the aminenucleophile compound, and wherein the functional group handle isselected from the group consisting of an azide group, an alkyne group,an alkyl halide group, a benzyl halide group, a thioether group, adisulfide group, an epoxide group, a thiol group, an alcohol group, adiol group, an ester group, and a boronic acid group.
 3. Thefunctionalized bile acid polymer of claim 1, wherein the aminenucleophile compound comprises a nitrogen cation bonded to the polymer.4. The functionalized bile acid material of claim 1, wherein Ycorresponds to an AB diblock polycarbonate copolymer.
 5. Afunctionalized bile acid material having a chemical structure ofStructure I:

wherein R corresponds to a steroid backbone of a bile acid; wherein Ycorresponds to a polymer comprising a polycarbonate structure; andwherein X′ corresponds to a nucleophile comprising a quaternary aminebonded to the polycarbonate structure of Y.
 6. The functionalized bileacid material of claim 5, wherein the bile acid is selected from thegroup consisting of cholic acid, chenodeoxycholic acid, lithocholicacid, deoxycholic acid, and glycocholic acid.
 7. The functionalized bileacid material of claim 5, wherein X′ further comprises an aminefunctional group covalently bonded to a carboxyl group of the bile acid.8. The functionalized bile acid material of claim 5, wherein Ycorresponds to an AB diblock polycarbonate copolymer.
 9. Afunctionalized bile acid material having a chemical structure ofStructure I:


10. The functionalized bile acid material of claim 5, wherein thefunctionalized bile acid material provides an anti-cancer therapeuticfunctionality.